THAT FINISH HAS TO BE ABSORBED BY THE WOOD FIBERS, GLASS IS IMPERMEABLE SO IT WILL NOT WORK ON A GLASS BOW. IT COULD BE USED ON ALL WOOD BOWS THAT DO NOT HAVE ANY SURFACE FINISH (POLYURETHANE, VARNISH, SHELLAC) BUT THERE ARE PROBABLY BETTER CHOICES WHEN IT COMES TO WEATHER ISSUES.